Which scan is described as being performed quickly by scanning thousands of ports per second on a fast network not obstructed by a firewall?

• A. INIT Scan
• B. Stealth Scan
• C. Xmas Scan
• D. ACK Flag Probe Scan

Answer: (A)

A fast, high-volume port sweep on a network that isn’t blocked by a firewall relies on a probing method that doesn’t require establishing full connections or triggering heavy detection. An INIT scan fits this description because it uses lightweight probes to quickly map a large number of ports, allowing thousands of probes per second when the network and filter rules are permissive. Since there’s little stateful interaction and no need to complete TCP handshakes, the scan can run at a very high speed.

Stealth scans are designed to avoid detection and logging, which typically slows them down and reduces throughput. Xmas scans and ACK flag probe scans rely on unusual flag usage or specific firewall rule behaviors, which can be dropped or filtered by many networks, preventing the same rapid sweep. In a fast, unobstructed environment, the INIT approach best matches the described scenario.